System Description

PRE-COLLISION: PRE-COLLISION SYSTEM: SYSTEM DESCRIPTION

1. PRE-COLLISION SAFETY SYSTEM DESCRIPTION

(a) The pre-collision safety system detects vehicles and obstacles in front of the vehicle and performs the following: 1) optimally uses system controls to avoid crashes, and 2) uses system controls to reduce impact during a crash.

2. PRE-COLLISION DETECTION OUTLINE

(a) Pre-collision detection

(1) The driving support ECU receives information about vehicles and obstacles in front of the vehicle from the millimeter wave radar sensor assembly and lane recognition camera sensor assembly. Then, based on vehicle speed, road conditions and obstacle location, the driving support ECU determines, in advance, the risk of a crash and if a crash is unavoidable.

(2) The driver monitor camera detects the direction that the driver's head is facing. When a potential crash is detected and the camera determines that the driver's head is not facing forward, it activates the pre-collision alarm controls in advance.

(3) If the possibility of collision is high and the driving attitude/conditions have not improved, the ECU will initiate warning control.

(b) Sudden braking detection

(1) The brake booster with master cylinder (skid control ECU) activates the pre-collision safety seat belts when it detects sudden braking. Sudden braking is determined based on brake oil pressure and other information from the master cylinder pressure sensor.

(c) Vehicle control impossible judgment

(1) The pre-collision safety seat belts are activated when it is determined that there is a high probability that the vehicle cannot be controlled. The judgment is based on vehicle stability information from the yaw rate sensor and steering angle sensor.

(d) Component





3. PRE-COLLISION SAFETY SYSTEM CONTROL DESCRIPTION





4. PRE-COLLISION ALARM CONTROL

(a) When the system determines that there is a risk of colliding with an obstacle in front of the vehicle, the multi-information display and warning buzzer are used to warn the driver and help with crash avoidance.

5. PRE-COLLISION SEAT BELT CONTROL

(a) When the system determines that a crash with an obstacle is unavoidable, that sudden braking has occurred, or that vehicle control is impossible, the system performs seat belt control. During seat belt control, slack in the seat belts is reduced, contributing to improved occupant safety.

6. PRE-COLLISION BRAKE ASSIST CONTROL

(a) When the system determines that there is a risk of colliding with an obstacle in front of the vehicle, brake assist is set to standby mode. Then, when the driver depresses the brake pedal, the hydraulic brake pressure is increased to improve braking effectiveness.

7. PRE-COLLISION BRAKE CONTROL

(a) When the system determines that a crash with an obstacle is unavoidable, the system performs brake control to reduce the vehicle speed.

8. PRE-COLLISION BRAKE CANCEL SWITCH

(a) When the pre-collision brake cancel switch in the glove box is turned on, the pre-collision alarm and pre-collision brake do not operate.

HINT
While the pre-collision brake cancel switch is on, the combination meter PCS indicator light blinks.

9. PRE-COLLISION SAFETY SYSTEM OPERATING CONDITION





HINT
o: Operation

X: No operation

*1: Inoperative parts are different depending on malfunction areas

*2: Only operates when seat belt is fastened

*3: Pre-collision seat belts may operate when brakes are suddenly applied

10. PRECAUTION FOR FRONT MILLIMETER WAVE RADAR SENSOR AND OBJECT RECOGNITION CAMERA

(a) When the millimeter wave radar sensor and lane recognition camera detect an object in front of the vehicle under the conditions described below, the driving support ECU may determine that a collision is unavoidable, and activates the pre-collision safety system. However, this is not abnormal.





HINT
* The pre-collision safety system does not activate when the pre-collision sensor detects safety cones and other plastic objects.
* The pre-collision system may or may not activate when the pre-collision sensor detects the following objects: people, bicycles, motorcycles, trees, animals and snow fences.